Dear all, may i first congratulate you on such a cracking site :thumb: Previous threads have helped me with a number of problems with my GS.
I mainly use the UK site but seek the learned advice from you good fellows 'over the water'
Ive got a '95 UK GS500. It started running poorly a while back, so stripped the carbs, gave them a good clean etc. Once assembled it started with no problems after leaving it on prime for a while. After a few minutes, the idle speed started dropping, before it eventually conked out.
It would start again, but only for a few seconds, then would not start at all. On leaving it for a couple of hours, it would start again, but after a few minutes it appeared to be starved of fuel again. The tank was full and the fuel lines and tap have been cleared.
I am guessing that this is caused by the floats not working properly? Any advice from other possible causes of these symptoms would be greatly appreciated :cheers:
Hey Murph....
Did you reconnect the fuel supply hose back to the lower T or the upper T at the back of the carbs? Should be hooked to the lower.
The fuel petcock at the tank should be turned to the straight down position to open fully l if it is slightly past or before its not open. I had the same type symptoms before realizing that I had turned it way past where it should be closing it back up. Inside the valve is an O that is rotated in alignment with the tank hole and the hose hookup. If its not straight 0 the hole is smaller for fuel. Won't keep up the proper amount of flow when running. I even drilled mine out a bit to provide a larger hole for gas to flow through. But it still has to be aligned almost perfectly.
Doublecheck the vacuum hose from the frame petcock to the carb. It may also be pinched.
Hope this helps, good luck.
Also, air box when reinstalled can pinch the fuel line if not routed correctly. Floats should not create the symtoms you describe.
cheers boys for your advice and promt replys
the main tap under the tank is vertical
the lower T does lead to the fuel tap.
I did notice that the right hand carb did not have a cap on the vacum pipe (where the left hand side has a tube leading to the rear of the fuel tap) Would this cause the problem?
No the tube sticking out on the right carb is not capped it is plugged internally.
Have you tried running the engine leaving the frame mounted petcock in the prime "stright up" position?
When you cleaned the carbs was there rust in there? Tank may be rusted.
It "sounds " from your description like you have a lack of fuel. Whether it be an old hose colapsing inside, screen in tank clogged, pinched hose somewhere or more rust in the carbs. My 96 had only 1694 miles when I got it and the tank had rust real bad in the bottom of it. Cleaned the carbs but as soon as I reinstalled the tank rust got right back in and started clogging the carbs immediatly. It sounds like there is only a trickle of fuel going to the carbs in your case. Filling the bowls with time but not refilling quick enough to run for extended period.
I ran a clear piece of 5/16 tubing straight from the tank to the carb inlet then opened the tank petcock and ran my bike like that so I could watch the fuel flow. When it didn't run for long in that manner. I knew my problem was in the carb.
many thanks for your replies. Have checked to see whether the pipes are bing pinched but they seem ok. Will try running clear tube straight to the carbs from the tank and see what happens.
Will keep you updated :thumb:
Quote from: murphcheers boys for your advice and promt replys
the main tap under the tank is vertical
the lower T does lead to the fuel tap.
I did notice that the right hand carb did not have a cap on the vacum pipe (where the left hand side has a tube leading to the rear of the fuel tap) Would this cause the problem?
OK right and left carbs should have caps on their plastic tops, and the left carb will need that line runnig from the vacuum spigot (1/2 way down on the right side of the left carb - facing the right carb) to the vacuum fitting on the petcock. Else you're sucking air ... and lots of it.
Cool.
Srinath.
Idle adjustment screw?
And, welcome to GStwin!
Cheers scratch- no the screw is fine and idle rate is correct. Just to recap, after leaving the bike for an hour, it will run fine for a few minutes then appear to have fuel starvation symptoms- ie idle dropping and spluttering before conking out. It would then not start again until you left it for a while.
I assumed that this was due to my floats not allowing enough fuel in (?) or a poor fuel supply (faulty tap or pinched hoses / collapsed hoses)
Ive now bought some clear hoses as suggested and will replace them tomorrow to see if a constant fuel supply is reaching the carbs.
changed the fuel lines with clear ones and installed an inline fuel filter just before the carbs. No lines are being pinched.
bugger- still happens after a few minutes. The fuel supply seems fine and checked the float levels using the clear tube method mentioned on this site. :(
One thing i did notice was that the routing of my carb breath hose differed from that in the diagram heading down instead of 'up and over'. The hose however is not restricted.
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